Double pulse laser produced plasma on metallic target in seawater: basic aspects and analytical approach

In this work, laser-induced breakdown spectroscopy has been applied in seawater using a dual pulse laser source. Fundamental aspects of laser-induced plasma under water as well as the effects of the first and the second laser pulses have been discussed. To investigate the laser-induced plasma temporal evolution, a set of experiments on a titanium target has been performed in water. The confinement effect of the surrounding environment generated by the first laser pulse on laser-induced plasma has been pointed out by the study of the electron number density. Finally, a preliminary experiment of quantitative chemical analysis of Ti, Cu, Pb, Sn, and Zn in submerged samples has been presented to prove the reproducibility of LIBS experiments in seawater and support the perspective of its application as in situ analytical technique.